Research On UUV Polar Integrated Navigation Based On SINS/DVL/USBL

With the increase of global temperature and the melting of ice and snow in the polar regions,the polar regions are rich in natural resources,and the competition for resources and space in the polar regions is fierce.Underwater vehicle is an indispensable tool for regional work,and its navigation and positioning ability is the prerequisite for all kinds of work.Aiming at the navigation problem of underwater vehicle in polar region,the integrated navigation system of strapdown inertial navigation in transverse coordinate system,Doppler and ultra-short baseline in polar region is presented in this paper.The main work of this paper is as follows:Firstly,a transverse coordinate system suitable for polar inertial navigation is adopted because the traditional inertial navigation mechanics is unable to locate in the polar region due to the fast convergence of meridians.The definition of transverse coordinate system is given,and the mechanics arrangement of inertial navigation is deduced.The error characteristics are emphatically analyzed and compared with the systematic errors of traditional coordinate system,which lays the foundation for subsequent integrated navigation with inertial navigation as the core.Secondly,the traditional damping and correction techniques of INS in transverse coordinate system are studied.In order to suppress the periodic oscillations of Schuler and Foucault,a horizontal damping network is designed under the external velocity information.At the same time,an azimuth damping network is designed to suppress the periodic oscillations of the Earth,which constitutes the total damping system of INS.The position of the system is re-adjusted by using the three-point calibration scheme based on the external position information.The heading error and gyro random constant drift are estimated and corrected.Then,the integrated navigation method of INS in transverse coordinate system,Doppler and ultra-short baseline is established.Based on the error equation of INS,the state model of INS is established.According to the basic principle of Doppler and ultrashort baseline,the state equation and measurement equation are given.Using Kalman filter as data fusion scheme,the combination mode of INS,Doppler and ultra-short baseline is realized respectively.The simulation results show that the transverse coordinate inertial navigation system and Doppler combination can effectively suppress the system error of INS,but the position error divergence of the combination can achieve better results for long-term navigation tasks using the combination of INS and ultra-short baseline.Moreover,the system composed of the three components has better accuracy and can meet the working requirements of underwater vehicle in the polar region.Finally,in view of the complex underwater environment and the phenomenon that the sensor is prone to abnormal measurements due to multipath effect,Huber estimation method is used to deal with the abnormal measurements noise,which improves the robustness of integrated navigation algorithm.In this paper,the algorithm steps of Kalman filter based on Huber estimation are given,and the non-Gaussian thick tail and continuous outliers in measurement noise are processed by using improved Huber cost function.The simulation results show that the method is effective.